Reproduction method and reproduction apparatus

ABSTRACT

This invention relates to a reproduction method and also to a reproduction apparatus adapted to transmit a first digital signal for main data of a piece of music and additional data accompanying the main data and including the number of the piece of music and the elapsed time on the track and a second digital signal for main data of the piece of music and accompanying absolute time data on a common digital interface.

BACKGROUND OF THE INVENTION

[0001] 1. Field of the Invention

[0002] This invention relates to a reproduction method and also to areproduction apparatus adapted to transmit a first digital signal formain data of a piece of music and additional data accompanying the maindata and including the number of the piece of music and the elapsed timeon the track and a second digital signal for main data of the piece ofmusic and accompanying absolute time data on a common digital interface.

[0003] 2. Related Background Art

[0004] The digital audio interface output of known compact disk (CD)players is adapted to produce, in addition to main data that are digitalaudio data, channel status data including a category code foridentifying the CD category of the CD disk to be played and user datacomprising Q codes, each including a track number and the elapsed timeof a piece of music on the track.

[0005] On the other hand, many known digital recording apparatus using adigital audio tape (DAT) or a mini-disk (MD) as recording medium aredesigned to automatically record start IDs and track numbers on therecording medium for a great convenience of the user on the basis of theCD category identified by decoding the channel status data and thesub-data including the track numbers and the elapsed time of each pieceof music recorded on the CD to be replayed as detected by decoding the Qcode of the user data when receiving data from the CD player by way ofthe digital audio interface.

[0006] Meanwhile, in recent years, standards for optical disks that aredifferent from known CDs and adapted to record high speed 1-bit digitalaudio signals for music have been proposed. Audio data addressed by theproposed standards are 1-bit audio signals obtained by subjectingcorresponding analog audio signals to a delta-sigma (ΔΣ) modulationprocess. A 1-bit audio signal is sampled with a very high samplingfrequency that is 64 times as high as the sampling frequency of 44.1 KHzof ordinary CDs. The signal is expressed in terms of a very highsampling frequency and a data word length with a very small number ofquantization bits and hence characterized by a wide transmissionfrequency band. Additionally, due to the ΔΣ modulation, it can secure awide dynamic range in the audio band that is a low frequency bandrelative to the over-sampling frequency that is 64 times as high as thesampling frequency of ordinary CDs.

[0007] An optical disk deals with high speed 1-bit audio signalsconforming to the proposed standards for new digital audio signals andshows audio characteristics by far more excellent than those of knownCDs. However, a recording system totally different from that of knownCDs has to be used for it and hence is not compatible with known CDs interms of information on the track numbers and the elapsed time of eachpiece of music as contained in the sub-data as well as other data.

[0008] Therefore, when producing a digital audio interface output in adisk replaying apparatus adapted to digital audio signals conforming tothe proposed new standards, the category code of the channel statusdata, the user data and other data generally have to be newly definedand managed.

[0009] However, the use of such newly defined data is totallydetrimental to the above identified convenience of recording start Idsand track numbers on the recording medium when the data are recorded byway of the digital interface to a known digital recording apparatus.

[0010] Particularly, with a reproduction apparatus adapted to bothdigital audio disks conforming to the new standards and existing CDs,there arises a confusing situation where the above convenience isavailable when replaying a CD whereas it is not available when replayinga new disk to a great inconvenience on the part of the user of theapparatus.

SUMMARY OF THE INVENTION

[0011] In view of the above identified circumstances, it is therefore anobject of the present invention to provide a reproduction method andreproduction apparatus adapted to use channel status data and user datain the format equivalent to that of CDs for the digital audio interfaceoutput when replaying a disk for digital audio signals recorded with asystem different from that of CDs so that the convenience ofautomatically recording start Ids and track numbers on the digitalrecording medium such as DAT or mini-disk can be ensured as in the caseof a CD.

[0012] Another object of the present invention is to provide areproduction apparatus and a reproduction method adapted to use channelstatus data and user data in the format equivalent to that of CDs forthe digital audio interface output particularly in the case of areproduction apparatus adapted to both digital audio disks conforming tothe new standards and existing CDs.

[0013] According to an aspect of the invention, the above objects areachieved by providing a reproduction apparatus adapted to selectivelyreplaying a first recording medium having a program area storing aplurality of programs formatted according to a first format and sub-dataincluding at least the passed-by addresses of each program and theprogram numbers; and

[0014] a second recording medium having a program area storing aplurality of programs formatted according to a second format differentfrom said first format and sub-data accompanying said programs andincluding absolute addresses and a control area for controllingrecording addresses expressed in terms of absolute addresses andcorresponding the programs stored in said program area;

[0015] said reproduction apparatus comprising:

[0016] a reproduction means for replaying the control area and theprogram area of said second recording medium;

[0017] a memory means for storing recording addresses expressed in termsof absolute addresses and corresponding to the programs recorded in thecontrol area of said second recording medium and replayed by saidreproduction means;

[0018] a sub-data generation means for generating the program number andthe passed-by addresses of the program currently being reproduced on thebasis of the absolute addresses reproduced from the program area of saidsecond recording medium by the recording addresses as expressed in termsof absolute addresses and corresponding to the programs stored in saidmemory means and also by said reproduction means; and

[0019] an interface output means for receiving as input the passed-byaddresses and the program number of each of the programs reproduced fromthe program area of said first recording medium when replaying saidfirst recording medium and receiving the passed-by addresses and theprogram number of the program currently being reproduced as generated bysaid sub-data generation means, transforming them and outputting them toa predetermined digital interface when replaying said second recordingmedium.

[0020] According to another aspect of the invention, there is provided areproduction apparatus adapted to selectively replaying a first layerhaving a program area storing a plurality of programs formattedaccording to a first format and sub-data including at least thepassed-by addresses of each program and the program numbers and a secondlayer having a program area storing a plurality of programs formattedaccording to a second format different from said first format andsub-data accompanying said programs and including absolute addresses anda control area for controlling recording addresses expressed in terms ofabsolute addresses and corresponding the programs stored in said programarea;

[0021] said reproduction apparatus comprising:

[0022] a reproduction means for selectively replaying the program areaof said first layer and the control area and the program area of saidsecond layer;

[0023] a memory means for storing recording addresses expressed in termsof absolute addresses and corresponding to the programs recorded in thecontrol area of said second layer and replayed by said reproductionmeans;

[0024] a sub-data generation means for generating the program number andthe passed-by addresses of the program currently being reproduced on thebasis of the absolute addresses reproduced from the program area of saidsecond layer by the recording addresses as expressed in terms ofabsolute addresses and corresponding to the programs stored in saidmemory means and also by said reproduction means; and

[0025] an interface output means for receiving as input the passed-byaddresses and the program number of each of the programs reproduced fromthe program area of said first layer when replaying said first layer andreceiving the passed-by addresses and the program number of the programcurrently being reproduced as generated by said sub-data generationmeans, transforming them and outputting them to a predetermined digitalinterface when replaying said second layer.

BRIEF DESCRIPTION OF THE DRAWINGS

[0026]FIG. 1 is a schematic block diagram of a disk replaying apparatusembodied according to the invention.

[0027]FIG. 2 is a schematic illustration of the data structure of asub-coding frame format applicable to known CDs.

[0028]FIG. 3 is a schematic illustration of the frame data structure ofa Q data applicable to known CDs.

[0029]FIG. 4 is a schematic illustration of the frame data structure ofa Q data in a program area applicable to known CDs.

[0030]FIG. 5 is a schematic illustration of the data structure of asub-frame conforming to the Digital Audio Interface Standards.

[0031]FIG. 6 is a schematic illustration of the data structure of aframe conforming to the Digital Audio Interface Standards.

[0032]FIG. 7 is a schematic illustration of the data structure ofchannel status data.

[0033]FIG. 8 is a schematic illustration of the data structure of userdata when the category of channel status data indicates the CD category.

[0034]FIG. 9 is a schematic illustration of the data structure when asub-frame conforming to the Digital Audio Interface Standards is used asuser data.

[0035]FIG. 10 is a schematic illustration of the data structure when asub-frame conforming to the Digital Audio Interface Standards is used aschannel status data.

[0036]FIG. 11A is a schematic illustration of the data structure of anHD disk applicable to the present invention.

[0037]FIG. 11B is a detailed illustration of the data structure of areaTOC shown in FIG. 11A.

[0038]FIG. 11C is a detailed illustration of the data structure of thetrack area shown in FIG. 11A.

[0039]FIG. 11D is a detailed illustration of the data structure of eachtrack of the track area shown in FIG. 11A.

[0040]FIG. 12 is an illustration of the data table that may be recordedin the track list in an area TOC data.

[0041]FIG. 13 is an illustration of the data table that may be recordedin the index list in an area TOC data.

[0042]FIG. 14 is an illustration of the data table of an audio header inthe audio sector of each track.

[0043]FIG. 15 is an illustration of the data table of frame info in theaudio header of each track.

[0044]FIG. 16 is a specific example of table of the track list and theindex list in an area TOC data.

[0045]FIG. 17 is a schematic illustration of the data structure of asub-Q-data.

[0046]FIG. 18 is a flow chart of the operation of generating tracknumbers, index numbers and elapsed time that can be used for the purposeof the invention.

[0047]FIG. 19 is a schematic illustration of the data structureindicating track numbers, index numbers and start times that can beactually generated on the basis of the table of FIG. 16.

[0048]FIG. 20 is a flow chart of the processing procedure according tothe invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0049] Now, the present invention will be described by referring to theaccompanying drawings that illustrate preferred embodiments ofreproduction apparatus and reproduction method according to theinvention.

[0050] The embodiment of reproduction apparatus according to theinvention as described hereinafter is adapted to replay music from acompact disk (CD) and also from a novel optical disk storing high speed1-bit digital audio signals and also output audio signals conforming tothe Digital Audio Interface Standards. An optical disk of the new typestoring high speed 1-bit digital audio signals will be referred to as anHD (high definition) disk hereinafter.

[0051] Each high speed 1-bit audio signal recorded on an HD disk isobtained by means of delta-sigma (ΔΣ) modulation of an analog audiosignal and has a data format of a data word length of 1-bit and asampling frequency of 2,8224 MHz (44.1 KHz×64).

[0052]FIG. 1 is a schematic block diagram of disk replaying apparatus 1embodied according to the invention.

[0053] Referring to FIG. 1, optical disk 2 is a multilayer diskcomprising a first layer storing multi-bit digital audio signals in theconventional CD format and a second layer storing 1-bit digital audiosignals in the new format referred to as the HD format.

[0054] In a different mode of carrying out the invention, a reproductionapparatus may be so arranged as to selectively carry and drive aconventional CD or an hinge device storing 1-bit digital audio signalsin the HD format.

[0055] The signal read out from the optical disk 2 by means of opticalpickup 3 is input to physical signal detector/processor 5 by way of RFamplifier 4.

[0056] In the case where the optical disk 2 is an HD disk or an HDlayer, the physical signal detector/processor 5 carries out an operationof physically processing the signal including EFM plus demodulation,product coding and descrambling and transmits a 1-bit delta-sigmamodulated digital audio signal having a sampling frequency of fsmultiplied by 64 (64×44.1 KHz=2.8224 MHz) to audio signal processor 6and additional information detector/processor 8.

[0057] On the other hand, in the case where the optical disk 2 is a CD,the physical signal detector/processor 5 carries out an operation ofphysically processing the signal including EFM demodulating and CIRC(cross interleaved Read-Solomon coding) and transmits a digital audiosignal sampled with a sampling frequency of fs (44.1 KHz) and having aquantization bit number of 16 bits to audio signal processor 11 andadditional information detector/processor 12.

[0058] The audio signal processor 6 demodulates the 1-bit digital audiosignal that is reproduced from the optical disk 2 and sampled with thesampling frequency of fs multiplied by 64 (64×44.1 KHz=2.8224 MHz) andthe rate converter 13 down-converts the 1-bit digital audio signalsampled with the sampling frequency fs multiplied by 64 (64×44.1KHz=2.8224 MHz) to a multi-bit digital audio signal having a samplingfrequency of f2 (44.1 KHz) and a quantization bit number of 16 bits thatare equivalent with those of a CD and transmits it to one of theterminals of first switch 14.

[0059] On the other hand, the additional information detector/processor11 demodulates the digital audio signal having a quantization bit numberof 16 bits that is reproduced from the optical disk 2 and sampled withthe sampling frequency of fs (44.1 KHz) and transmits to the otherterminal of the first switch 14.

[0060] Then, the multi-bit digital audio signal selected by the firstswitch 14 is fed to interface output section 7.

[0061] The digital audio interface output section 7 outputs themulti-bit digital signal typically as digital audio interface outputconforming to the IEC958 format.

[0062] The additional information detector/processor 8 separates all theinformation other than the audio signal from the data string containingsaid 1-bit digital audio signal. More specifically, it detects timeinformation TCP, which will be described hereinafter, from the headerinformation contained in said data string and transmits it to sub-dataconverter/generator 9. Additionally, it extracts information on thestart time of each track and that of each index such as track start timecodes and index start time codes from the control information arrangedat the head and the trail of said data string and stores the extractedinformation in memory 10.

[0063] The sub-data converter/generator 9 converts and generatessub-data such as channel status data and user data that conform to theDigital Interface Standards on CDs by means of said time information TCPfed from the additional information detector/processor and said trackstart time information and index start time information stored in saidmemory 10.

[0064] The sub-data generates by the sub-data converter/generator 9 suchas channel status data and user data to one of the terminals of secondswitch 15.

[0065] On the other hand, the additional information detector/processor12 separates all the information other than the audio signal from thedata string containing said multi-bit digital audio signal.Additionally, it extracts information conforming to the DigitalInterface Standards on CDs such as channel status data and user data andtransmits it to the other terminal of switch 15.

[0066] Then, the sub-data such as channel status data and user dataselected by said switch 15 are transmitted to said digital audiointerface output section 7 and synthetically combined with the multi-bitdigital audio signal from the audio signal processor 6 or the audiosignal processor 11. Then, it outputs the obtained data conforming tothe Digital Audio Interface Standards to digital output terminal 1.

[0067] The first switch 14 and the second switch 15 are controlled fortheir switching operations by a control signal output from the controlsection 16 on the basis of the outcome of the operation of determiningif a CD or an HD or if a CD layer or an HD layer, whichever appropriate,is to be handled.

[0068] Now, sub-data, or channel status data and user data conforming tothe CD Standards, that can be converted and generated by the sub-dataconverter/generator 10 by means of the additional information extractedfrom the 1-bit digital audio signals from the optical disk 2 will bediscussed hereinafter.

[0069] According to the CD Standards, there are sub-data (P, Q, R, S, T,U, V, W) formed on a frame by frame basis that can be read out when thedisk is driven for ordinary replay on a track by track basis. FIG. 2 isa schematic illustration of the data structure of a sub-coding frameformat of a compact disk audio system (conforming to the IEC(International Electro-technical Commission) 908 Standard). Sub-data Pthrough W are contained in each frame by 98 bits including sync bits S₀and S₁ for a sync pattern. P represents information on the intervalbetween two pieces on a track and R through W represent information onstill pictures and characters. Q represents most of the informationconverted and generated by the additional information detector/processor9 including track numbers and the elapsed time on each of the tracks aswell as the absolute time (minute, second, frame).

[0070]FIG. 3 shows a format applicable to a Q code. The 96 bits otherthan the sync bits of S₀ and S₁ include 4 CONTROL bits indicating thepresence or absence of emphasis and if copying the piece is permitted orprohibited, 4 address (ADR) bits indicating the data mode, 72 Q databits and 16 cyclic redundancy check (CRC) bits for the generation ofparity check codes. The number of address (ADR) bits will be reduced to1 when the data in the program area are being reproduced.

[0071]FIG. 4 is a schematic illustration of the frame data structure ofa Q data including only an address (ADR) bit. It includes track no TNO,index number X, the elapsed time on the track (minute (MIN), second(SEC), frame (FRAME)), the absolute time (minute (AMIN), second (ASEC),frame (AFRAME) from the head of the disk and CRC. Note that the elapsedtime on the track is that of a track with a specific track number.

[0072]FIG. 5 is a schematic illustration of the data format of asub-frame conforming to the Digital Audio Interface Standards (IEC-958Standards). FIG. 6 is a schematic illustration of the data structure ofa frame containing sub-frames as shown in FIG. 5.

[0073] The synchronization preamble (Sync Preamble), user data (U bit),channel status data (C bit) and other data exist in each frame inaddition to audio data for the left and right channels.

[0074]FIG. 7 is a schematic illustration of the data format of channelstatus data. The data contains a category code for identifying the typeof apparatus, the sampling frequency fs and CONTROL bits for indicatingthe presence or absence of emphasis.

[0075]FIG. 8 is a schematic illustration of the data format of a userdata when the category code of FIG. 7 is “10000000”, indicating that thesignal source is a CD reproduction apparatus. Here, codes Q through Ware listed to exclude P code and, particularly, the 96 bits Q code willbe extracted therefrom.

[0076]FIG. 9 and FIG. 10 show examples of data including user data (U)and channel status data (C) that can be actually output along with audiodata.

[0077] Thus, as described above, a digital output of a CD playercontains channel status data indicating the CD category and user dataindicating the track number and the elapsed time of the track.

[0078] On the other hand, according to the above described newlyestablished standards for optical disks (typically referred to as SuperAudio CD Standards), a start address that corresponds to the absolutetime of the start of a track in the audio area is written inTrack_List_(—)2 in the area TOC data. Only the time code contained inthe initial header of each audio sector that corresponds to the absolutetime of the start can be read out during an ordinary operation ofreproducing data from a track.

[0079]FIG. 11A is a schematic illustration of the data structure of theaudio area on an optical disk conforming to the Standards, where each ofthe two area TOCs arranged on the opposite sides of the track area has aconfiguration as shown in FIG. 11B. Track_Start_Time_Code of each trackis described in Track_List_(—)2 in the area TOC as shown in the syntaxof FIG. 12. Index start time code Index_Start_TC of each index number asshown in the syntax of FIG. 13 is described in Index_List of FIG. 11B.

[0080] On the other hand, Audio Sector as shown in FIG. 11D is providedon each track as shown in FIG. 11C in the track area of FIG. 11A andFrame_Info as shown in the syntax of FIG. 14 is described in AudioHeader in the Audio Sector. More specifically, Time_Code of each frameis described there as shown in FIG. 15.

[0081] As described above, according to the HD standards, only the timecode (absolute time) of each frame can be read out from a track areathat is a program area during an ordinary operation of reproducing datafrom a track unlike the CD format. In other words, information such astrack numbers and the elapsed time of each track is not recorded.Therefore, it is not possible to display track numbers and the elapsedtime of each track.

[0082] In order to overcome this inconvenience, the disk replayingapparatus 1 firstly reads out area TOC (Table of Contents) data andstores it in memory 8 as shown in FIG. 1 when a disk is placed inposition. Thus, the memory 8 stores a table of TRACK LIST 2 and INDEXLIST as shown in FIG. 16.

[0083] For driving the optical disk 2 for data reproduction and addinguser data (U bit) to its digital output, Q data as shown in FIG. 17 hasto be produced by additional information detector/processor 9 through adata conversion/generation process.

[0084] Now, a conversion processing operation of a sub-data, will bedescribed by referring to FIG. 18. Firstly, the time code (absolutetime) of the audio header has to be read out as TCP for each frame whileth_e optical disk 2 is driven for data reproduction. Then, in Step S1,the absolute time TCA (minute M, second S, frame F) of the TCP iswritten as shown in FIG. 17.

[0085] Then, in Step S2, Track_Start_Time_Code (TC2) of Track No. 2(TNO.2) is compared with the above TCP. If TCP is smaller than TC2, theoperation proceeds to Step S3, where the current track number isspecified as TNO.1. In Step S4, TC1 of Track Number 1 (TNO.1) issubtracted from the TCP to produce elapsed time TCN (minute, second,frame).

[0086] After Step S4, the operation proceeds to the processing sequenceof *1 surrounded by broken lines in FIG. 18, where the index number(IDX) in the track number TNO.1 is determined.

[0087] In Step S5, Index_Start_TC of INDEX 2 of the track number TNO. 1in Index_List is compared with the above TCP. If the above TCP issmaller than Index_Start_TC of INDEX 2, the operation proceeds to StepS6, where the index number is determined to be equal to “1”. If, on theother hand, it is found in Step S5 that the above TCP is greater thanIndex_Start_TC of INDEX 2, the operation proceeds to Step S7, whereIndex_Start_TC of INDEX 3 of the track number TNO. 1 is compared withthe above TCP. If the above TCP is smaller than Index_Start_TC of INDEX3, the operation proceeds to Step S8, wheere the index number isdetermined to be equal to “2”. If, on the other hand, it is found inStep S7 that the above TCP is greater than Index_Start_TC of INDEX 3,the operation proceeds to Step S9, where Index_Start_TC of INDEXM of thetrack number TNO.1 is compared with the above TCP. If the above TCP issmaller than Index_Start_TC of INDEXM, the operation proceeds to StepS10, where the index number is determined to be equal to “M−1”. If, onthe other hand, it is found in Step S9 that the above TCP is greaterthan Index_Start_TC of INDEXM, the operation proceeds to Step S11, whereIndex_Start_TC of INDEXM of the track number TNO. 1 is compared with theabove TCP. If the above TCP is smaller than Index_Start_TC of INDEXM+1,the operation proceeds to Step S12, where the index number is determinedto be equal to “M”.

[0088] Then, the operation returns to Step S2 and if it is found in StepS2 that the above TCP is greater than the above TC2, the operationproceeds to Step S2, where Track_Start_Time_Code (TC3) of Track Number 3(TNO. 3) is compared with the above TCP. If the above TCP is smallerthan TC3, the operation proceeds to Step S22, where the current tracknumber TNO. is determined to be equal to “2”. Then, in Step S23, TC2 ofthe track number TNO. 2 is subtracted from TCP to obtain the elapsedtime TCN (minute, second, frame).

[0089] After the above Step S23, the operation proceeds to theprocessing sequence of *2 surrounded by broken lines, where the indexnumber (IDX) in the track number TNO.2 is determined. Since thissequence is similar to that of *1 above, it will not be described hereany further.

[0090] Then, in Step S31, if the above TCP is smaller than TCN of thetack number N (TNO.N), the operation proceeds to Step S32, where thecurrent track number TNO. is determined to be equal to N−1. In Step S33,TC(N−1) of the track number TNO.(N−1) is subtracted from TCP to obtainthe elapsed time TCN (minute, second, frame).

[0091] After the above Step S33, the operation proceeds to theprocessing sequence of *N−1 surrounded broken lines, where the indexnumber (IDX) in the track number TNO.N−1 is determined. Since thissequence is similar to that of *1 above, it will not be described hereany further.

[0092] If it is found in Step S31 that the above TCP is greater than theN-th TCN of the track number TNO, the operation proceeds to Step S41,where Track_Start_Time_Code (TCN+1) of the track number N+1 (TNO.N+1) iscompared with the above TCP. If it is found that TCP is smaller thanTCN+1, the operation proceeds to Step S42, where the current tracknumber TNO is determined to be equal to “N”. Then, in Step S43, TCN ofthe track number N (TCN. N) is subtracted from TCP to obtain the elapsedtime TCN (minute, second, frame).

[0093] After the above Step S43, the operation proceeds to theprocessing sequence of *N surrounded by broken lines, where the indexnumber (IDX) in the track number INO.N is determined. Since thissequence is similar to that of *1 above, it will not be described hereany further.

[0094] Then, in the disk replaying apparatus 1, the sub-dataconverter/generator 9 turns TCP into absolute time TCA as shown in FIG.18, using TCP read out by the additional information detector/processor8 and the table stored in the memory 10 as shown in FIG. 16. Thereafter,the disk replaying apparatus 1 compares the track start time code ofeach track with TCP, starting from the track number TNO. 2. TNO of FIG.17 that is greater than the N-th TC of the track number TNO and smallerthan the N+1-th TC will be equal to N. The value obtained by subtractingthe N-th TC of TNO from TCP represents the elapsed time of the track TCN(minute, second, frame) of FIG. 17. Then, each index start time code ofTNO. N in the index list is compared with TCP to determine the currentindex number (IDX). Thus, Q data as shown in FIG. 17 can be preparedwith the above described flow of operation of conversion/generation.Then, fixed value data such as CONTROL and address ADA shown in FIG. 4are added thereto to produce complete Q data.

[0095] If the current absolute time is 7 minute, 40 second, 33 frame inthe list of area TOC shown in FIG. 16, then the track number TNO will be“2” and the elapsed time TCN will be 2 minute, 10 second, frame 33,whereas IDX will be “2”.

[0096] Now, the operation of the above embodiment will be describedfurther by referring to the flow chart of FIG. 18 and also to FIG. 19.

[0097] Firstly, TCP “7 minute, 40 second, 33 frame” as read out by theadditional information detector/processor 9 is written into TCA of FIG.17. Then, Track_Start_Time_Code (TC2) “5 minute, 30 second, 00 frame” ofthe track with the track number 2 (TNO. 2) is compared with the aboveTCP. Since TCP is greater than TC2, the operation proceeds to Step S21,where Track_Start_Time_Code (TC3) “11 minute, 40 second, 00 frame” ofthe track with the track number 3 (TNO. 3) is compared with the aboveTCP. Since TCP is smaller than TC3, the operation proceeds to Step S22,where the track number TNO is made equal to “2”. Then, in Step S23, TC2is subtracted from TCP to obtain 2 minutes, 10 seconds, 33 frames asTCN, or the elapsed time of the track number 2.

[0098] Also, “6 minute, 10 second, 00 frame” of INDEX 2 is compared withthe above TCP and, since TCP is greater of the two, TC “8 minute, 10second, 00 frame” of INDEX 3 is compared with the above TCP. Since TCPis smaller of the two, the index number will be made equal to “2”.

[0099] Thus, to convert the additional information read out from theoptical disk 2 by means of the optical pickup 3 of the disk replayingapparatus 1 into data corresponding to Q code of the sub-data of a CD,the data of the area TOC is read out by the additional informationdetector/processor 8 firstly when the disk is placed in position andstored in the memory 2. For an ordinary track replaying operation, thetime code in the header is read out by the additional informationdetector/processor 8 and converted into channel status data and userdata Q code equivalent to that of CDs by the user dataconverter/generator 9, referring to the information on the track list inthe area TOC data stored in the memory 10.

[0100] Thus, the conventional digital recorder that receives the digitalinterface output by way of the output terminal 11 identifies the CDcategory by decoding the channel status data and detects the sub-data ofthe CD including the track number and the elapsed time by decoding the Qcode of the user data. Then, it automatically records the start Id andthe track number corresponding to the detected data on the recordingmedium to a great advantage for the operation of the digital recorder.

[0101] For example, the value obtained by subtracting the start addressof the N-th address in the track list from the time code address beingreproduced will correspond to the elapsed time on the track.

[0102] Note that channel status data is more often than not uniquelydefined by the category and the parameters of the equipment to be used.For example, channel status data can be generated for a new optical diskby fixing the category code to CD, the sampling frequency to 44.1 KHzand the emphasis to off.

[0103] This operation of the present invention will be briefly discussedby referring to FIG. 10.

[0104] Firstly, in Step 101, it is determined if the CD layer or the HDlayer of the mounted optical disk that is to be replayed. If it isdetermined in Step 101 that the CD layer is specified by the user forreplaying, the operation proceeds to Step 102, where the TOC area of theCD layer is replayed firstly to access the program area and retrieve thenecessary data therefrom on the basis of the obtained TOC information.Then, in Step 103, the sub-data annexed to the main-data of the digitalaudio signal reproduced from the program area in Step 102. If, on theother hand, it is determined in Step 101 that the HD layer is specifiedby the user for replaying, the operation proceeds to Step 105, where theTOC area of the CD layer is replayed firstly and then, in Step 106, thearea TOC information is stored in the memory. In Step 107, the programarea is accessed and the necessary data is retrieved therefrom on thebasis of the obtained control information on the area TOC. Then, in Step108, the program number and the passed-by addresses of the program beingreplayed are generated on the basis of the recording addresses expressedin terms of absolute addresses of each program stored in the memory andthe absolute addresses reproduced from said program area.

[0105] Thereafter, in Step 109, the first switch and the second switchof FIG. 1 are turned to the HD side under the control of the controlsection. While the flow chart of FIG. 20 is described above in terms ofa multi-layer disk, the flow chart applies to the use of a CD and an HDdisk by modifying Step 101 to determine if the CD or the HD disk is tobe replayed.

[0106] With the above described method, the additional information of anovel optical disk can be converted into channel status data and userdata equivalent to those of a CD, which can then be used as digitalaudio interface output.

[0107] While a multi-bit digital signal of 16 bits with a samplingfrequency of fs (Hz) conforming to the existing CD standards and outputfrom the digital interface output section is produced and stored in someother recording medium in the above embodiment, it may alternatively beso arranged that a piece of music is divided on the basis of thesub-data including channel status data and user data output from thesub-data converter/generator 9 when the 1-bit digital audio signalsampled with a sampling frequency of fs multiplied by 64 (64×44.1KHz=2,8224 MHz) and output from the audio signal output section 6 inFIG. 1 is recorded on some other recording medium.

[0108] Thus, according to the present invention, when replaying a diskstoring digital audio signals recorded according to an HD system that isdifferent from the CD system, the additional information including thetrack number and the elapsed time of each piece of music are detectedand converted into data equivalent to channel status data and user dataconforming to the CD standards for the digital audio interface, whichdata are then output to the digital interface output. With thisarrangement, the advantage of automatically recording the start Ids andthe track numbers on the recording medium can also be maid availablewhen recording a digital recorder such as DAT or mini-disk.

1. A reproduction apparatus adapted to selectively replaying a first recording medium having a program area storing a plurality of programs formatted according to a first format and sub-data including at least the passed-by addresses of each program and the program numbers; and a second recording medium having a program area storing a plurality of programs formatted according to a second format different from said first format and sub-data accompanying said programs and including absolute addresses and a control area for controlling recording addresses expressed in terms of absolute addresses and corresponding the programs stored in said program area; said reproduction apparatus comprising: a reproduction means for replaying the control area and the program area of said second recording medium; a memory means for storing recording addresses expressed in terms of absolute addresses and corresponding to the programs recorded in the control area of said second recording medium and replayed by said reproduction means; a sub-data generation means for generating the program number and the passed-by addresses of the program currently being reproduced on the basis of the absolute addresses reproduced from the program area of said second recording medium by the recording addresses as expressed in terms of absolute addresses and corresponding to the programs stored in said memory means and also by said reproduction means; and an interface output means for receiving as input the passed-by addresses and the program number of each of the programs reproduced from the program area of said first recording medium when replaying said first recording medium and receiving the passed-by addresses and the program number of the program currently being reproduced as generated by said sub-data generation means, transforming them and outputting them to a predetermined digital interface when replaying said second recording medium.
 2. A reproduction apparatus according to claim 1 , wherein said first format is that of a digital signal sampled with a sampling frequency of Fs (Hz) and having a quantization bit number of m (m≧2, integer).
 3. A reproduction apparatus according to claim 2 , wherein said second format is that of a digital signal sampled with a sampling frequency of Fs (Hz) multiplied by n (n≧2, integer) and having a quantization bit number of 1 bit.
 4. A reproduction apparatus according to claim 1 , further comprising a conversion means for converting the program in the program area of the second format into a program of the first format.
 5. A reproduction apparatus according to claim 1 , wherein said digital interface conforms to the IEC 958 Standards.
 6. A reproduction apparatus adapted to selectively replaying a first layer having a program area storing a plurality of programs formatted according to a first format and sub-data including at least the passed-by addresses of each program and the program numbers and a second layer having a program area storing a plurality of programs formatted according to a second format different from said first format and sub-data accompanying said programs and including absolute addresses and a control area for controlling recording addresses expressed in terms of absolute addresses and corresponding the programs stored in said program area; said reproduction apparatus comprising: a reproduction means for selectively replaying the program area of said first layer and control area and the program area of said second layer; a memory means for storing recording addresses expressed in terms of absolute addresses and corresponding to the programs recorded in the control area of said second layer and replayed by said reproduction means; a sub-data generation means for generating the program number and the passed-by addresses of the program currently being reproduced on the basis of the absolute addresses reproduced from the program area of said second layer by the recording addresses as expressed in terms of absolute addresses and corresponding to the programs stored in said memory means and also by said reproduction means; and an interface output means for receiving as input the passed-by addresses and the program number of each of the programs reproduced from the program area of said first layer when replaying said first layer and receiving the passed-by addresses and the program number of the program currently being reproduced as generated by said sub-data generation means, transforming them and outputting them to a predetermined digital interface when replaying said second layer.
 7. A reproduction apparatus according to claim 6 , wherein said first format is that of a digital signal sampled with a sampling frequency of Fs (Hz) and having a quantization bit number of m (m≧2, integer).
 8. A reproduction apparatus according to claim 7 , wherein said second format is tht of a digital signal sampled with a sampling frequency of Fs (Hz) multiplied by n (n≧2, integer) and having a quantization bit number of 1 bit.
 9. A reproduction apparatus according to claim 6 , further comprising a conversion means for converting the program in the program area of the second format into a program of the first format.
 10. A reproduction apparatus according to claim 6 , wherein said digital interface conforms to the IEC 958 Standards.
 11. A reproduction method for selectively replaying a first recording medium having a program area storing a plurality of programs formatted according to a first format and sub-data including at least the passed-by addresses of each program and the program numbers; and a second recording medium having a program area storing a plurality of programs formatted according to a second format different from said first format and sub-data accompanying said programs and including absolute addresses and a control area for controlling recording addresses expressed in terms of absolute addresses and corresponding the programs stored in said program area; said reproduction method comprising: a replaying step of replaying the control area and the program area of said second recording medium; a storing step of storing recording addresses expressed in terms of absolute addresses and corresponding to the programs recorded in the control area of said second recording medium and replayed by said reproduction means; a sub-data generating step of generating the program number and the passed-by addresses of the program currently being reproduced on the basis of the absolute addresses reproduced from the program area of said second recording medium by the recording addresses as expressed in terms of absolute addresses and corresponding to the programs stored in said memory means and also by said reproduction means; and an interface output step of receiving as input the passed-by addresses and the program number of each of the programs reproduced from the program area of said first recording medium when replaying said first recording medium and receiving the passed-by addresses and the program number of the program currently being reproduced as generated by said sub-data generation means, transforming them and outputting them to a predetermined digital interface when replaying said second recording medium.
 12. A reproduction method for selectively replaying a first layer having a program area storing a plurality of programs formatted according to a first format and sub-data including at least the passed-by addresses of each program and the program numbers and a second layer having a program area storing a plurality of programs formatted according to a second format different from said first format and sub-data accompanying said programs and including absolute addresses and a control area for controlling recording addresses expressed in terms of absolute addresses and corresponding the programs stored in said program area; said reproduction method comprising: a replaying step of selectively replaying the program area of said first layer and the control area and the program area of said second layer; a storing step of storing recording addresses expressed in terms of absolute addresses and corresponding to the programs recorded in the control area of said second layer and replayed by said reproduction means; a sub-data generating step of generating the program number and the passed-by addresses of the program currently being reproduced on the basis of the absolute addresses reproduced from the program area of said second layer by the recording addresses as expressed in terms of absolute addresses and corresponding to the programs stored in said memory means and also by said reproduction means; and an interface output step of receiving as input the passed-by addresses and the program number of each of the programs reproduced from the program area of said first layer when replaying said first layer and receiving the passed-by addresses and the program number of the program currently being reproduced as generated by said sub-data generation means, transforming them and outputting them to a predetermined digital interface when replaying said second layer. 